Conventional insulating jackets or holders for single cold beverage containers, such as cans and bottles are formed of vinyl or polyurethane tubing originally designed for pipe insulation, or of foamed polystyrene which is usually rather rigid and which is sometimes provided with an end ring of a more flexible material having a lip which contacts the container. Although these materials provide good insulation, insertion and removal of the beverage container into and from the jacket is difficult. The difficulty in removing and inserting the beverage container results from the relatively high coefficient of friction between the container and jacket material, the pressure pocket developed when the container is inserted into the jacket and the suction created when the container is withdrawn from the jacket. Where the container has been retained within a conventional jacket for a period of time sufficient to allow the condensation on the container to dry, the jacket material tends to adhere to the container and to cause damage to the jacket upon removal of the container from the jacket.
Conventional insulating jackets for beverage containers are disclosed in U.S. Pat. No. 3,603,106 to Ryan, No. 3,743,130 to Jorgensen and No. 3,905,511 to Groendal. The Ryan and Jorgensen patents disclose cylindrical jackets which do not have means for opening the side wall of the jacket to facilitate insertion and removal of the container. The Groendal patent discloses a jacket having hingedly coupled upper and lower sections to provide a closed-top jacket for the container.
U.S. Pat. No. 3,906,192 to Damois discloses an insulating cover for a water heater. The cover comprises a multilayer material and has a zipper joining two cover sections to facilitate mounting of the cover about a water heater. The cover of the Damois patent is not adapted nor suitable for use with beverage containers.